A new study seeks to define what it means when someone pursues a partner who is "out of their league."

Researchers representing the University of Michigan and the Santa Fe Institute analyzed heterosexual dating markets in four major U.S. cities – New York, Boston, Chicago and Seattle – based on messaging data from a popular unnamed online dating website.

The results of the study showed men and women alike pursued partners who were 25 percent more desirable than themselves. The study also found pursuers used different messaging strategies depending on how desirable a potential partner was.

"We have so many folk theories about how dating works that have not been scientifically tested," Elizabeth Bruch, a sociologist with the University of Michigan and the study’s lead author, said in a statement. "Data from online dating gives us a window on the strategies that people use to find partners."

A person's "desirability" was determined by how many messages, especially initial messages, a user received. It also explored who contacted those people.

"If you are contacted by people who are themselves desirable, then you are presumptively more desirable yourself," the study said. And that desirability played out differently for women than for men.

"Older women are less desirable, while older men are more so," the authors noted. Desirability for the average man peaks at 50 then declines, while desirability for the average woman steadily declines from the age of 18 until they are 60.

Ethnicity factored in considerably, too.

"In keeping with previous work, there is also a clear and consistent dependence on ethnicity, with Asian women and white men being the most desirable potential mates by our measures across all four cities," the authors said.

As for messaging, researchers learned users put more effort into contacting more desirable partners.

"Both men and women tend to write substantially longer messages to more desirable partners, up to twice as long in some cases," read an excerpt from the study.